Instantiating different number of objects per spline
These should work. The one uses the splines points and a multiplier as an input integer for the amount of points to evaluate per spline.
The other uses a integer list you can edit, each input corresponding to a spine in your spine list.
Both of these output a list of locations which can be fed into a Instancer node.
A 3d viewer node can also be handy to see which integer list input corresponds to which spline.